1,507 research outputs found
Sea Otter, Enhydra lutris, mortalities in California, 1968 through 1993
Sea otter, Enhydra lutris, mortality in California and the relative contribution from specific causes was assessed for the 26 years from 1968 through 1993. There were 2,082 dead sea otters recorded from Tomales Bay (Marin County) south to Bluff Cove (Los Angeles County) during that period. The average number of carcasses recorded was 80 per year and seven per month. Sex was identified in 87% (n=1,819) of the cases and was composed of 47% female and 53% male. A relative age was assigned to 97% (n=2,017) of the cases and was composed of 28% pup, 18% subadult and 54% adult.
Specific causes of death were determined for 26% (n=55 1) of the cases. The majority of these (n=381) were considered to be due to natural causes and included the following specific causes: shark bitten (n=78), probably shark bitten (n=106), other natural causes (n=140), and mating wounds (n=57). The remaining (n=170) were considered to be due to human-related causes and included the following specific causes: shot
(n=72), probably shot (n=8), net drowned (n=76), and other human causes (n=14).
The large proportion of carcasses without an identified specific cause of death prompted a more detailed necropsy effort in 1992 and 1993. During that period, 78 of the 232 recovered carcasses were examined by veterinary pathologists and a specific cause of death was determined in 76% (n=59) of the cases. This effort identified a wide range of specific causes of death that otherwise may have been categorized as "unknown without trauma". Considering the variety of diseases diagnosed in this expanded necropsy program, it would be prudent to continue this level of examination to refine our knowledge of sea otter pathology. (48pp.
Structural disorder versus chiral magnetism in CrNbS
The crystal structure of a disordered form of CrNbS has been
characterized using diffraction and inelastic scattering of synchrotron
radiation. In contrast to the previously reported symmetry (P622), the
crystal can be described by a regular twinning of an average P6 structure
with three disordered positions of the Cr ions. Short-range correlations of the
occupational disorder result in a quite intense and structured diffuse
scattering; a static nature of the disorder was unambiguously attributed by the
inelastic x-ray scattering. The diffuse scattering has been modeled using a
reverse Monte-Carlo algorithm assuming a disorder of the Cr sub-lattice only.
The observed correlated disorder of the Cr sub-lattice reduces the temperature
of the magnetic ordering from 130 K to 88 K and drastically modifies the field
dependence of the magnetization as it is evidenced by the SQUID magnetometery.
We conclude, that in contrast to the helicoidal spin structure assumed for
P622 form, the compound under study is ferromagnetically ordered with a
pronounced in-plane anisotropy
Systematic review of the current status of cadaveric simulation for surgical training
Background:
There is growing interest in and provision of cadaveric simulation courses for surgical trainees. This is being driven by the need to modernize and improve the efficiency of surgical training within the current challenging training climate. The objective of this systematic review is to describe and evaluate the evidence for cadaveric simulation in postgraduate surgical training.
Methods:
A PRISMA‐compliant systematic literature review of studies that prospectively evaluated a cadaveric simulation training intervention for surgical trainees was undertaken. All relevant databases and trial registries were searched to January 2019. Methodological rigour was assessed using the widely validated Medical Education Research Quality Index (MERSQI) tool.
Results:
A total of 51 studies were included, involving 2002 surgical trainees across 69 cadaveric training interventions. Of these, 22 assessed the impact of the cadaveric training intervention using only subjective measures, five measured impact by change in learner knowledge, and 23 used objective tools to assess change in learner behaviour after training. Only one study assessed patient outcome and demonstrated transfer of skill from the simulated environment to the workplace. Of the included studies, 67 per cent had weak methodology (MERSQI score less than 10·7).
Conclusion:
There is an abundance of relatively low‐quality evidence showing that cadaveric simulation induces short‐term skill acquisition as measured by objective means. There is currently a lack of evidence of skill retention, and of transfer of skills following training into the live operating theatre
Estimating fuel channel bore from fuel grab load trace data
Detailed measurements of the graphite core fuel channels are made by specialist inspection equipment during planned outages, typically every 18 months to 3 years. The bores of the graphite fuel bricks are obtained during these inspections and are used to provide important information about the health of the core. Additionally, less detailed online monitoring data is obtained much more frequently during refuelling events, called the fuel grab load trace (FGLT), which can be also used to infer the health of the graphite core. This paper describes the process of creating a model which isolates a component of the refuelling data and maps it directly to dimensional measurements of fuel channel bore. The model is created from a combination of the theoretical understanding of the physical interactions of the fuel stringer during refuelling events and several years of refuelling and inspection data to estimate suitable model parameters. Initially the model created was a coarse estimation of FGLT to fuel bore dimension but through refinements a much more accurate model has been created. An application of this model is shown through a case study of a recent outage where estimations were made on refuelling data and were compared to previously unseen inspection data
Experimental Investigation of the Nature of the Knee in the Primary Cosmic Ray Energy Spectrum with the GAMMA experiment
We present preliminary results obtained by a novel difference method for the
study of the nature of the knee in the energy spectrum of the primary cosmic
radiation. We have applied this method to data from the GAMMA experiment in
Armenia. The analysis provides evidence for the possible existence of a nearby
source of primary cosmic rays in the Southern hemisphere.Comment: 17 pages, 5 figure
Spider-silk inspired polymeric networks by harnessing the mechanical potential of β-sheets through network guided assembly.
The high toughness of natural spider-silk is attributed to their unique β-sheet secondary structures. However, the preparation of mechanically strong β-sheet rich materials remains a significant challenge due to challenges involved in processing the polymers/proteins, and managing the assembly of the hydrophobic residues. Inspired by spider-silk, our approach effectively utilizes the superior mechanical toughness and stability afforded by localised β-sheet domains within an amorphous network. Using a grafting-from polymerisation approach within an amorphous hydrophilic network allows for spatially controlled growth of poly(valine) and poly(valine-r-glycine) as β-sheet forming polypeptides via N-carboxyanhydride ring opening polymerisation. The resulting continuous β-sheet nanocrystal network exhibits improved compressive strength and stiffness over the initial network lacking β-sheets of up to 30 MPa (300 times greater than the initial network) and 6 MPa (100 times greater than the initial network) respectively. The network demonstrates improved resistance to strong acid, base and protein denaturants over 28 days
Magnetic Phase Transitions in the double spin-chains compound
We report high-resolution x-ray diffraction, muon-spin-rotation spectroscopic
and specific heat measurements in the double spin-chains compound . The x-ray diffraction results show that the crystal structure of
~is orthorhombic down to T=10K. Anisotropic line-broadening of
the diffraction peaks is observed, indicating disorder along the spin chains.
Muon spin relaxation and specific heat measurements show that
\~undergoes a phase transition to a magnetic ordered state at .
The specific heat data exhibits a second -like peak at , which increases with increasing magnetic field similarly way to
that found in spin-ladder compounds.Comment: 6 pages, 6 fifures, to appear in Physica
An immunotherapy survivor population: health-related quality of life and toxicity in patients with metastatic melanoma treated with immune checkpoint inhibitors
© The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Purpose The immune checkpoint inhibitors (ICIs) have resulted in subgroups of patients with metastatic melanoma achievinghigh-quality durable responses. Metastatic melanoma survivors are a new population in the era of cancer survivorship. The aimofthis study was to evaluate metastatic melanoma survivors in terms of health-related quality of life (HRQoL), immune-relatedadverse events (irAEs) and exposure to immunosuppressive agents in a large single centre in the UK.Methods We defined the survivor population as patients with a diagnosis of metastatic melanoma who achieved a durableresponse to an ICI and had been followed-up for a minimum of 12 months from initiation of ICI without disease progression.HRQoL was assessed using SF-36. Electronic health records were accessed to collect data on demographics, treatments, irAEsand survival. HRQoL data was compared with two norm-based datasets.Results Eighty-four metastatic melanoma survivors were eligible and 87% (N = 73) completed the SF-36. ICI-related toxicity ofany grade occurred in 92%of patients and 43%had experienced a grade 3 or 4 toxicity. Almost half (49%) of the patients requiredsteroids for the treatment of ICI-related toxicity, whilst 14% required treatment with an immunosuppressive agent beyondsteroids.Melanoma survivors had statistically significant lower HRQoL scores with regard to physical, social and physical rolefunctioning and general health compared with the normative population. There was a trend towards inferior scores in patientswith previous exposure to ipilimumab compared with those never exposed to ipilimumab.Conclusions Our results show that metastatic melanoma survivors have potentially experienced significant ICI-related toxicityand experience significant impairments in specific HRQoL domains. Future service planning is required to meet this population’sunique survivorship needs.Peer reviewe
Crystal structure and high-field magnetism of La2CuO4
Neutron diffraction was used to determine the crystal structure and magnetic
ordering pattern of a La2CuO4 single crystal, with and without applied magnetic
field. A previously unreported, subtle monoclinic distortion of the crystal
structure away from the orthorhombic space group Bmab was detected. The
distortion is also present in lightly Sr-doped crystals. A refinement of the
crystal structure shows that the deviation from orthorhombic symmetry is
predominantly determined by displacements of the apical oxygen atoms. An
in-plane magnetic field is observed to drive a continuous reorientation of the
copper spins from the orthorhombic b-axis to the c-axis, directly confirming
predictions based on prior magnetoresistance and Raman scattering experiments.
A spin-flop transition induced by a c-axis oriented field previously reported
for non-stoichiometric La2CuO4 is also observed, but the transition field (11.5
T) is significantly larger than that in the previous work
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